Hi, I just recently got my bike and i'm not sure if this is a safety thing or if I lost a part riding, but I just filled up my tank really full, to the point where I may have overfilled it. I noticed later after parking the bike that it is sitting in a small amount of gasoline, which is dripping from what appears to be a small metal tube protruding from the gas tank right above the left carburetor. I looked at a parts schematic on bikebandit and i think this is the water drain hose, but I'm not sure if it's leaking because I overfilled the tank or because there's something that has fallen off. Any help would be greatly appreciated, thanks.

Open the gas cap. Is there fuel around it in the overfull area? If so, that's it. There should be a hose going down to the ground. Some California tanks have an extra tube coming out for "emissions". It could be coming from that (if you have 2 metal tubes under the tank: a straight one and a bent one). Still sounds like over filling the tank. Only fill up to the bottom of the fill tube. Don't top it off.
Also check the rubber gasket on the fuel cap. If worn out, you'll need a new one. That can let fuel leak out when the bike is on the side stand, too.

PS: It helps to know what year your bike is and where you're located, due to emission standards that make the fuel system slightly different.

Like adidas says, your problem is "I just filled up my tank really full, to the point where I may have overfilled it.".
Because of the flush fit fuel cap,there is a drain tube from under the cap to let water out if it rains. If you over fill it, fuel comes out there. The tube goes down through the fuel tank and ends where you see the leak.

The same thing happens when you drink too much beer, it ends up dribbling out of a little tube just below your beer tank.

Yeah, overfilled it. Thanks for the help you guys.